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The second poster is right, there is no fish per gallon rule. Even the inches per gallon rule is pretty misleading. Looking at the size/type of fish to get an idea of the bio load and territorial requirements is a much more important factor.

as pointed out in your resource, the inch per gallon rule is really inaccurate. 10 1 inch tetras will produce much less waste than a single 10 inch fish. a 10 inch long goldfish/oscar/other bulky fish will produce much
more waste than a 10 inch eel.

If you take your time to do the research FIRST, you can successfully set-up and keep ANY type of aquarium with ease."Not using a quarantine tank is like playing Russian roulette. Nobody wins the game, some people just get to play longer than others." - Anthony CalfoFishless CycleCycling with FishMarine Aquarium Info [URL="http://saltwater.aquaticcommunity.com/"]

as pointed out in your resource, the inch per gallon rule is really inaccurate. 10 1 inch tetras will produce much less waste than a single 10 inch fish. a 10 inch long goldfish/oscar/other bulky fish will produce much
more waste than a 10 inch eel.

+ 1 To the above replies. As stated in the thread you referenced: {Have you noticed a similar theme here wrt the replies?}

The point is simple: there are sooooooo many exceptions to the rule how can you use it?

Just another example of how the 'rule' does not apply in the real world:
My 11" Oscar would not be very comfortable in a 10 - 20 - 30 - 40 or 55g tank but is quite at home in his 6' 100G.

IF the 'rule' could be applied effectively at all it would be for very small fish [with small bioloads] in very small tanks & as mentioned their activity level matters also.

Naturally, This is still dependent upon being able to maintain stability & good water quality.

This is far far more difficult in smaller tanks because the margin for error is much smaller, A smaller volume of water is far more susceptible to dramatic changes in water parameters.

Last edited by Goes to 11!; 02-08-2013 at 02:08 AM.

Gas mileage isn't everythingOIIIIIIIOLack of planning on your part does not constitute an emergency on my part.Why pretend there are no stupid questions? Actually, There are many stupid questions: "Should I drink this bleach?" Is just one example.
Having said that, Just because it's a stupid question doesn't mean that it shouldn't be asked. It's better to know.A warm beer is better than a cold beer. Because nothing is better than a cold beer, and a warm beer is better than nothing.

It's a decent rule of thumb for beginners and small fish, but should be thrown out the window for larger fish, goldfish, or people who know what they're doing.

If you have to boil it down, the things you need to keep in mind are:

Filters handling bio-load
Doing frequent enough water changes
Oxygen in the water
Overcrowding

And I will certainly say keeping enough oxygen in the water is usually extremely easy and usually doesn't need to be worried about at all. If the other 3 are accomplished you can stock well past an inch of fish per gallon, or well below it if the fish are territorial and would be overcrowded. It depends much more on the type of fish than the rule.

No one has mentioned it yet so I will. Aqadvisor.com is a great resource for stocking levels.

The rule is too crude a judgement of how many fish can be kept in a tank. I can keep a single betta in a 90g with no filter and tons of plants, or I could keep a school of 200 rasbora in a bare 90g with a Fluval Fx5. When judging how many fish are appropriate for a tank, you should really look at it holistically rather than trying to comply with all these different rules.

+1 to everyone's replies as was constantly told to me when i joined. also you must factor in this...say take for example my 10 gallon tank which is currently stocked with 4 ornate tetras and 6 flame tetras.

Yes this is JUST under overstocking, however to compensate for this i upped the WC to 2 fifty percent water changes per week for this tank. I also vacuum the gravel on one of these two water changes.

but i only have the tank this heavily stocked for two reasons

1. they are all peaceful fish
2. two of my ornate tetras died before i decided to combine the schools. so to save myself money i decided to combine the schools.

Result, i keep up on my water changes in my planted 10 gallon tank, and the fish are doing very well. both schools seem to enjoy the extra companionship.

So no, there's not a inch per gallon rule.

However you stock you do have to take in account everything the senior members have stated. The personality of the fish in regards to compatibility, the water conditions (including filtration), and keeping a schedule for water changes. These three things will make or break your stock in the tank.

Good luck with your journey. Keep us posted. also do the FISHLESS CYCLE if you haven't already...you'll be thankful you did later.

Beginners will find a way get it wrong & then they will find another way & then eventually we will tell them that it is not a rule worth applying which is where we should have started in the first place.

Originally Posted by Zander

No one has mentioned it yet so I will. Aqadvisor.com is a great resource for stocking levels.

No one has mentioned it because it is ok to use as a sketchpad - but NOT a final draft.

Gas mileage isn't everythingOIIIIIIIOLack of planning on your part does not constitute an emergency on my part.Why pretend there are no stupid questions? Actually, There are many stupid questions: "Should I drink this bleach?" Is just one example.
Having said that, Just because it's a stupid question doesn't mean that it shouldn't be asked. It's better to know.A warm beer is better than a cold beer. Because nothing is better than a cold beer, and a warm beer is better than nothing.